Galerie de l'Institut, formerly Bouquinerie de l'Institut, has been specializing in prints by prestigious artists since 1954, and its longevity on the print market has earned it a great reputation both in France and internationally. Marc and Yves Lebouc's keen eye, research and meticulous study of subjects over many years have earned them recognition asexperts in their field, enabling them to assess the value and authenticity of a print. Marc Lebouc is an expert before the Paris Court of Appeal, and Yves Lebouc is a member of the Compagnie Nationale des Experts.

 Marc and Yves Lebouc are not just private buyers, but also colleagues from all over the world who, like us, are players in the art market, uncompromising about the quality of the works offered to the public and concerned about their ethics.

 Backed by the presence of the two experts, Galerie de l'Institut offers its customers, on request, certificates of authenticity for works acquired at the gallery. Marc and Yves Lebouc are also authorized to issue certificates of authenticity for prints (etchings, lithographs, illustrated books) by Marc Chagall and Pablo Picasso that are brought to them (see expertise conditions below).

Chagall expertise

Marc and Yves Lebouc have been commissioned by the Comité Marc Chagall to appraise the artist's graphic works. Over 1,000 references make up the Catalogue raisonné of lithographs, in addition to over a hundred illustrated books and engravings.

The Galerie de l'Institut is the only authority recognized by the Comité Marc Chagall to authenticate the artist's prints. Copies of certificates and attestations are systematically filed for registration with the Comité Marc Chagall.

Picasso expertise

Marc and Yves Lebouc are trusted by the Picasso Administration to issue certificates of authenticity for prints by Pablo Picasso. This involves over 2,000 engravings referenced for graphic works and 156 illustrated books.

The experts draw on all the literature in the catalogs raisonnés, but above all on their extensive technical experience and the large number of works they have studied.

Extremely meticulous in their analysis of the engravings, lithographs and linocuts presented to them, Marc and Yves Lebouc work rigorously, with the support of the Picasso Administration, to ensure that any print that does not conform (by its signature, or by falsification of the original print) is listed as such. Copies of certificates and attestations are systematically filed with the Picasso Administration for registration.

Expertise conditions

Works submitted for appraisal must be physically presented to the experts, who will issue an opinion after studying and verifying them. A certificate of authenticity or attestation is invoiced at €250 excluding VAT. In the case of works sold by the Galerie, certificates are given to the purchaser free of charge on request.




To learn more about the gallery, the works available, our expertise service or our exhibitions: